FIG. 11 is a drawing of an example of a conventional inkjet head cleaning device. The illustrated inkjet head cleaning device 500 is provided with an ultrasonic cleaner 502 disposed in a lower section of a head cleaning container 501 which contains therein a cleaning solution 503. The frequency of the ultrasonic cleaner 502 can be changed by a frequency converter (not illustrated in the drawing). In the inkjet head cleaning device 500, an inkjet head 60 is immersed in the cleaning solution 503 contained in the head cleaning container 501 and cleaned with the vibration frequency being changed by the ultrasonic cleaner 502.